National Aeronautics and Space Administration

Goddard Space Flight Center

ICESat banner

ICESat

ICESat

ICESat (Ice, Cloud,and land Elevation Satellite) was the benchmark Earth Observing System
mission for measuring ice sheet mass balance, cloud and aerosol heights, as well as land
topography and vegetation characteristics. From 2003 to 2009, the ICESat mission provided
multi-year elevation data needed to determine ice sheet mass balance as well as cloud
property information, especially for stratospheric clouds common over polar areas. It also
provided topography and vegetation data around the globe, in addition to the polar-specific
coverage over the Greenland and Antarctic ice sheets.

Update: ICESat Mission Status Report

August 17, 2010

The Ice, Cloud, and Land Elevation Satellite (ICESat) was successfully decommissioned
from operations Saturday August 14, 2010, at approximately 17:37:00 Greenwich Meridian Time (GMT).
As part of the final stage of mission decommissioning, the flight operations team passivated
the spacecraft in compliance with NASA policy and regulations that seek to “minimize the
creation of orbital debris by government and non-government operations in space in order to
preserve the space environment for future generations.“ To passivate ICESat, the team sent
and activated a series of commands previously stored in the on-board computer to remove all
forms of stored energy from the spacecraft. The team verified successful passivation after
confirming negative acquisition of signal by ground network tracking stations. Re-entry
information will be issued by the NASA Orbital Debris Program Office from data provided by
the United States Space Surveillance Network.

ICESat decommissioning and passivation activities started on June 23, 2010,
with a series of sixteen controlled burns to lower the orbit and deplete all of
the spacecraft’s residual propellant. On July 15, the propellant was fully depleted after
the 15th burn. After completion of the orbit -lowering burns, NASA Headquarters approved a
special study to collect data from the Global Positioning System (GPS) on board the spacecraft,
as it started its natural orbit decay. Since July 15, the ICESat operations team has been
retrieving, collecting and processing GPS data. Congratulations to the ICESat team for a successful
seven years of operations.

July 28, 2010

NASA's Ice, Cloud, and land Elevation satellite (ICESat) ended its science mission in
February 2010 with the failure of the last of its three lasers. In June, NASA's Science
Mission Directorate approved a plan to lower the spacecraft's orbit so that it would
re-enter the atmosphere by August-September 2010. A series of thruster burns on the
spacecraft conducted June 23-July 14 slowly lowered ICESat's orbit, minimizing the time
until it re-enters Earth's atmosphere and breaks up. Some pieces of the spacecraft,
weighing collectively about 200 pounds, are expected to survive re-entry. The risk of
harm coming to anyone on Earth from this debris is estimated to be very low. The U.S.
Space Surveillance Network, operated by the Department of Defense, will closely monitor
the orbit of this debris during its final days. NASA will issue periodic updates regarding
the debris re-entry.